AJV validate schema with JSONPath strings - node.js

Question

I'm trying to create a JSON schema that can support validating JSON objects with property values that can either be regular JSON types OR strings representing valid JSONpath expressions.
So for example, given this schema:
{
"$schema": "http://json-schema.org/draft-07/schema",
"properties": {
"age": {
"type": "number"
}
}
}
Either of these JSON objects could be valid:
{
"age": 30
}
{
"age" "$.age"
}
I've gotten stuck trying to add a custom keyword called jsonPath like this:
{
"$schema": "http://json-schema.org/draft-07/schema",
"properties": {
"age": {
"type": "number",
"jsonPath": true
}
}
}
ajv.addKeyword('jsonPath', {
valid: true,
compile: () => data => {
return /^\$./.test(data)
}
})
Ideally I would love to just be able to check if a given property value is a valid JSONPath string and if so, approve it. Otherwise let ajv run it's own validation.
Thanks for any help!

Answer 1

I don't know if you can prevent other keywords from running. There are multiple ways to apply checks in JSON Schema to the same location, so this would likely be pretty difficult and probably not something that's supported by ajv.
You could build this into your schema.
{
"$schema": "http://json-schema.org/draft-07/schema",
"properties": {
"age": {
"anyOf": [
{
"type": "number"
},
{
"pattern": "REGEX FOR JSON PATH"
}
]
}
}
}
You could de-duplicate the regex by using definitions and referencing it using $ref.